Map of Simcoe Muskoka

Infectious Diseases


Measles is a disease caused by a virus and is also known as “red measles” or “rubeola”. Symptoms of measles include fever, coughing, runny nose and a rash. Measles is a highly infectious disease and can be easily prevented by a vaccine. For more information, see the health unit's fact sheet on measles and measles vaccine.

Simcoe Muskoka
Technical Notes

Simcoe Muskoka

The following graphs show the number of measles cases in Simcoe Muskoka between 1991 and 2021, and 2000 and 2021, respectively. Since 2000, there have been between zero and two reported cases of measles in Simcoe Muskoka every year. In 2021, zero cases of measles were reported in Simcoe Muskoka.



In the five years before the introduction of the two-dose vaccine, there were nearly 600 cases of measles in Simcoe Muskoka (from 1991 to 1996). The two-dose measles vaccine was introduced in 1996/1997 which led to a significant decrease in the number of measles cases reported in Simcoe Muskoka and across Ontario. Since 1996, there have been a total of six cases reported in Simcoe Muskoka in the 25 year time span.



For more information on measles, please see Public Health Ontario’s Measles Infographic.


The following graph shows the incidence rate of measles in Simcoe Muskoka and Ontario between 2000 and 2021. In 2021, the incidence rate for measles in both Simcoe Muskoka and Ontario overall was 0.0 cases per 100,000.


More detailed data for Ontario and each health unit can be found on Public Health Ontario’s interactive Reportable Disease Trends in Ontario tool.

Technical Notes

There are many factors that influence how many cases are reported to the health unit, as explained on the Infectious Diseases page. It is unclear to what extent the global COVID-19 pandemic has influenced the reporting and spread of other infectious diseases – counts and rates of disease since 2020 should be interpreted with caution.

Provincial definitions classify cases as confirmed, probable or suspect based on clinical and/or laboratory diagnostic criteria. The provincial case definition for measles changed in April 2009 to include a definition for probable cases whereas before there was no such classification. The definitions of confirmed and probable cases from 2009 onwards are comparable to confirmed cases before 2009.

Page last updated August 19, 2022